Meanwhile, iOS users downloaded games 2.23 billion times in the third quarter, compared with about 540 million downloads for entertainment apps, the No. 2 finisher.
But when it comes to the popularity of individual apps, messaging and social media services rule. By Sensor Tower's measure, the top five apps ranked by combined downloads on Google Play and the App Store were, in order: WhatsApp, Facebook, Messenger, Instagram and Snapchat.
The mobile game with the highest number of downloads was Subway Surfers, which ranked eighth overall on Sensor Tower's list. That's an indication that—while games remain popular as a category—they are still outpaced by messaging and social media apps on an individual basis.
eMarketer estimates that smartphone gamers in the US will number 121.4 million this year, with their ranks growing to 138.4 million by 2021.